Macintosh IIci gives chimes of death; memory trouble?

[tanuki65]

So, I acquired a Macintosh IIci recently (see https://68kmla.org/forums/index.php?/topic/25123-macintosh-iici-wont-start-up/).

It occasionally booted pre-recap, but now that it's been recapped it just starts, gives the boot chime, goes for a minute or two, and then sounds the Chimes of Death. Nothing displays on the monitor.

I do not have the ethernet card installed. Any ideas? (It's parity memory (with 9 chips) and I might have nicked a chip. Trying with two SIMMs in just give the startup chime and then the Chimes of Death immediately after.)

P.S. Thank you, unity, for suggesting a re-cap. The sound works now. 

 

[olePigeon]

I would start with swapping chips around until it doesn't death chime.

 

[tanuki65]

Swapping chips? I don't have any other 30-pin SIMMs. Could it be ESD?

 

[trag]

You mention just two SIMMs installed.  SIMMs must be installed in matched sets of four.    If you're using the built-in video, there must be four SIMMs in bank A.

 

[unity]

Brian fart time - does the parity RAM require the optional parity controller? I forget which way it goes. All I know is I have a new IIci board with a parity controller added and did some light reading way back.

 

[Elfen]

The "normal" IIci does not use parity, so that should not be a problem. If it is a system that was in a high altitude area like snow mountain towns of Colorado or if it is a US Gov't system, then it would have parity circuitry. So lets assume that is does not have parity support... you need 4 of the same SIMMs per bank. At minimum you need Bank A filled, so all your SIMM Group testing must be done there.

Now, what kind of SIMMs are you using? And, you did the recapping? You checked the lines going to the SIMMs?

 

[tanuki65]

SIMMs have been tried in 4-SIMM and 2-SIMM configurations. Uniserver did the recapping; he says it works great. They are 16MB SIMMs. Please read my original post.

 

[lopaka1998]

Try the simms in a different mac if you have one.  Or replace them - maybe with something smaller just for testing purposes. 

Also - have you had your power supply recapped?  Unstable power could be causing your problems, perhaps.  If the voltage isn't high enough, or there is too much ripple coming out, it could cause something like this.  This would also explain why Uniserver says it works... He tested i'm sure using a fixed / recapped power supply. 

Regardless of whether this problem is being caused by the power supply, I highly suggest you have it done before turning it on again.  Otherwise, you'll just over-stress the computer and perhaps kill something in the process.

SIMMs have been tried in 4-SIMM and 2-SIMM configurations. Uniserver did the recapping; he says it works great. They are 16MB SIMMs. Please read my original post.

 

[tanuki65]

Does uniserver recap power supplies?

 

[tanuki65]

It worked once after PSU reseating, but afterwards death chimed.

 

[olePigeon]

Hmm.

Is there any difference if you leave it plugged in for a good 10 minutes before turning it on?

 

[tanuki65]

I'll try.

 

[Elfen]

SIMMs have been tried in 4-SIMM and 2-SIMM configurations. Uniserver did the recapping; he says it works great. They are 16MB SIMMs. Please read my original post.

The IIciIIcx are 32bit machines so 2-SIMM configuration will never work on these machines as that is a 16bit configuration.

16MB SIMMs? Trying to achieve 64MB/128MB IIci? I would suspect them. If Uniserver recapped the machine, that means that he had tested it on his RAM and his PSU, I know he guarantees his work.

Try 4MB SIMMs to get 16MB on Bank A and see if it works. If the problem persists, then it's the PSU needs recapping. You checked the voltages coming out of the rear floppy port?

 

[unity]

I think his point about trying two versus four SIMMs is that there is very much a different response. As expected. Two SIMMS is really as good as booting with none, and he get near immediate death chimes. With four, it takes much longer - which is why I too suspect bad or incorrect RAM.

 

[tanuki65]

I have checked no floppy voltages. I was trying to acheive a 64MB IIci that could be upgraded to a 128MB IIci if needed. I'd like to have at least 32MB in my IIci, since I'll be running System 7.5.4 (yes, I have a copy) and RAM-hungry programs such as Netscape Navigator 2.02, iCab 2.9.9, and Photoshop. (And QuickTime 4.) Would 4 of http://www.ebay.com/itm/161019154549 be good? If so, I'll order them this weekend and if that doesn't help, PM uniserver. Any thoughts?

 

[RalfK]

The IIci has two banks of DRAM. Bank A is also used as video buffer. Bank A is the right one, means the bank directed to harddisk and floppy. Bank A must be populated.

There are two logic boards, one uses parity, the other does not. In the front left corner there is a chip (or foot print) called "PGC" on position "UM3" near RESET switch. If this IC is installed than you must use parity SIMMs. Otherwise you can use standard SIMMs or parity SIMMs.

16MB SIMMs are ok. 80nsec or less.

 

[Elfen]

RalfK is right.

Unity, I agree but... lets continue else where for a moment...

Tanuki65 - Here is the pin outs to the floppy port of any given Mac with external floppy drive:

https://support.apple.com/kb/TA48050?locale=en_US&viewlocale=en_US

In it pins:

1 to 4 is CGND - Chassis ground

5 is -12V

6 is +5V

7 is +12V

8 is +12V

9 is N/C Not connected

With the Mac IIci closed and turned on, how are you going to check for voltages from your powersupply in the inside of your machine? You can't. You measure the voltages from the floppy port at these pin numbers. Any reading other that what is stated means that there is something wrong with the board or PSU. Since the board was recapped by an expert, then the problem is with the PSU. But to figure that out, you need to measure it and see it.

Now - if all the voltages are on point and rock steady - then the problem is with the RAM.

 

[tanuki65]

I'll try on Saturday.

Is there any difference if you leave it plugged in for a good 10 minutes before turning it on?

No, I tried. Also, I no longer need to use the trick of turning on the power strip and pressing the power key on the keyboard at the same time. Perhaps the recap fixed it?

 

[tanuki65]

Floppy voltages are stable.